SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecba1f19342da72558afe9038932da5fbbe61592d293ab5707f72e5b22c9c7d4' 
  AND token = 'xHNUw4LiPuRRUL4B3bbdez1yimZCcK8+DdaUJ0pdy44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}